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OpenFOAM-6/src/finiteVolume/fields/fvPatchFields/doc/boundaryConditions.dox
2018-06-19 12:01:50 +01:00

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/*---------------------------------------------------------------------------*\
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\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
\page pageBoundaryConditions Boundary Conditions
\ref grpBoundaryConditions are required to 'close' the simulation problem.
Careful attention should be applied to their selection so as to create a
well-posed system of equations, which can be solved numerically.
\section secBoundaryConditionsOverview Overview
The set of available \ref grpBoundaryConditions comprise of basic, turbulent and
thermophysical types.
\subsection secBC1 Basic boundary conditions
- \ref grpConstraintBoundaryConditions
- \ref grpInletBoundaryConditions
- \ref grpOutletBoundaryConditions
- \ref grpGenericBoundaryConditions
- \ref grpCoupledBoundaryConditions
- \ref grpWallBoundaryConditions
\subsection secBC2 Turbulent flow boundary conditions
- \ref grpRASBoundaryConditions
\subsection secBC3 Thermophysical boundary conditions
- \ref grpThermoBoundaryConditions
\section secWallFunctions Wall-functions
Wall-functions in OpenFOAM are modelled as boundary conditions, applied to
the viscosity for momentum, and thermal diffusivity for energy.
Wall-functions
- \ref grpWallFunctions
Thermal wall-functions for incompressible flow
- \ref grpIcoWallFunctions
Thermal wall-functions for compressible flow
- \ref grpCmpWallFunctions
\section secBoundaryConditions Typical usage for pressure-velocity systems
The choice as to the most appropriate set of boundary conditions is dictated by
the type of flow problem. In many cases, multiple possible selections exist;
the following tables offer suggestions for subsonic flow.
subsonic inlet (flow specified):
\table
Variable | Symbol | Type
pressure | p | \link Foam::zeroGradientFvPatchField zeroGradient\endlink
velocity | U | \link Foam::fixedValueFvPatchField fixedValue\endlink
transported property | - | \link Foam::fixedValueFvPatchField fixedValue\endlink
derived property | - | \link Foam::calculatedFvPatchField calculated\endlink or \link Foam::zeroGradientFvPatchField zeroGradient\endlink
\endtable
subsonic outlet:
\table
Variable | Symbol | Type
pressure | p | \link Foam::fixedValueFvPatchField fixedValue\endlink
velocity | U | \link Foam::inletOutletFvPatchField inletOutlet\endlink or \link Foam::pressureInletOutletVelocityFvPatchVectorField pressureInletOutletVelocity\endlink
transported property | - | \link Foam::inletOutletFvPatchField inletOutlet\endlink
derived property | - | \link Foam::calculatedFvPatchField calculated\endlink or \link Foam::zeroGradientFvPatchField zeroGradient\endlink
\endtable
wall (impermeable, non-slip):
\table
Variable | Symbol | Type
pressure | p | \link Foam::zeroGradientFvPatchField zeroGradient\endlink
velocity | U | \link Foam::fixedValueFvPatchField fixedValue\endlink
transported property | - | \link Foam::fixedValueFvPatchField fixedValue\endlink
derived property | - | \link Foam::calculatedFvPatchField calculated\endlink or \link Foam::zeroGradientFvPatchField zeroGradient\endlink
\endtable
\*---------------------------------------------------------------------------*/